Present fencing systems require erection of structural support posts at some predetermined spacing after which a roll of plastic fencing material is secured at one end to a post and then tensioned from a structural support post at an opposite end so as to stretch the plastic fencing material across the plurality of structural support posts. After stretching, the plastic fencing material is secured to the intermediary structural support posts. Dependent upon the length of the fence to be erected, a great deal of force is required to tension an elongated fence. Accordingly, power driven tools are required to tension an elongated fence.
In an attempt to overcome such disadvantages, a self-tensioning fencing system as disclosed in U.S. Pat. No. 5,409,196 ("the '196 patent") commonly assigned with the instant application and incorporated herein in its entirety by reference, has been developed. According to the invention of the '196 patent, it is possible to tension a plastic grid material or any plastic fencing material across a plurality of structural support posts without the need for full tensioning of the entire length of the plastic fencing material prior to the plastic fencing material being secured to the structural support posts. To achieve this goal, a fastening system is used which is adaptable to both existing and new structural support posts of all common types, such as wood, steel tube and rolled steel sections. An installation method is used to tension the plastic fencing material without the need for specialized equipment after only a manual pre-tensioning of the plastic fencing material.
The self-tensioning fencing system of the '196 patent includes a mounting batten, made of plastic or metal, which is mounted directly to a structural support such as a fence post using standard nails, screws or bolts as required according to the type of a particular fence post. Alternatively, the mounting batten is produced integral with a support post. The mounting batten may be a solid or a thick walled hollow section plastic extrusion or a metal form. The mounting batten is secured to the structural support post so as to space the plastic grid material away from the support post to allow the plastic grid material to be tensioned at a spacing from the structural support posts.
In the system of the '196 patent, a channel batten may be made of pre-coated cold rolled steel or rigid plastic and mounted over the mounting batten and serves to clamp plastic fencing material between the mounting batten and the channel batten. The channel batten when drawn tight against the mounting batten, serves not only to firmly attach the fencing material to the support post but acts as a tensioning device.
The amount of tensioning take-up provided by the channel batten is dependent upon the respective cross-sectional dimensions of the mounting batten and the channel batten. In a typical application, the tensioning capability of the channel batten is in the range of 3/8 of an inch to 7/8 of an inch at each support post, and preferably 5/8 of an inch, which is variable dependent upon the plastic grid material used and the size and shape of the mounting batten and the channel batten. Since full tension is not applied to the entire length of plastic fencing material until each channel batten is secured to a respective mounting batten, the system of the '196 patent can accommodate a varying terrain.
A preferred form of grid-like sheet material used between fence posts, known as an integral geogrid, is commercially available from The Tensar Corporation of Atlanta, Ga. ("Tensar") and is made by the process disclosed in U.S. Pat. No. 4,374,798 ("the '798 patent"), the subject matter of which is incorporated herein in its entirety by reference. Preferably, uniaxially-oriented geogrid materials as disclosed in the '798 patent are used as fencing materials according to this invention, although biaxial geogrids or grid materials that have been made by different techniques such as woven, knitted or netted grid materials formed of various polymers including the polyolefins, polyamides, polyesters and the like or fiberglass, may be used. In addition, it is possible that felt-like fabrics including woven or non-woven, solid or perforated geofabrics, geonets, or even composite materials including some form of geofabric and/or geogrid laminate or solid plastic sheet materials may be used as the tensioned fencing material according to this invention. All of such materials are sometimes referred to herein and in the appended claims as "grid-like sheets of material", "polygrid" or "geogrid", whether they are formed with apertures or not.